Patients with documented, measurable or evaluable adenocarcinoma of the pancreas that is locally advanced, metastatic, or otherwise inoperable, who are candidates for second-line therapy after failing first-line therapy with FOLFIRINOX, will be entered into this phase 1b, multicenter, open-label, non-randomized, dose-escalation per cohort study. The trial is designed to evaluate the safety, tolerability, DLT(s), and MTD of escalating doses of PRI-724, a CBP/ β- catenin inhibitor, when administered in combination with a standard dose of gemcitabine. Correlative studies include characterization of the PK profiles of PRI-724 and gemcitabine, evaluation of the utility of potential PD markers of PRI-724 activity, as well as preliminary assessment of the antineoplastic activity of PRI-724 plus gemcitabine in this patient population.